1. Field of the Invention
The present invention relates to the art of electrical connector, more particularly, to a cable assembly having conductive wires extending through longitudinal side wall of a shielding of an electrical connector thereby providing a low profile, but EMI free environment to ensure signal transmission.
2. Description of the Related Art
A cable assembly is commonly used to interconnect two separate electrical systems and establish an electrical connection therebetween. The assembly typically includes a cable and two cable end connectors respectively connected to one end of the cable. The cable can be a coaxial cable, a flat cable, or a multi-wire cable. The cable can be electrically connected with terminals of the cable end connectors by several commonly used technologies, i.e., soldering, crimping, or IDC (Insulation Displacement Contact) technology.
With the popularization of portable electronic device, such as desktop computer and notebook computer, and with the development of high-speed signal transmission technology, the cable assembly used to transmit signals in such devices is also required to develop a minimized diameter for the cable as well as keeping a low profile figuration for the cable end connector, such that the assembly does not occupy too much space in the device. Meanwhile, when the cable assembly is used to transmit high-speed signal, the cable end connector is commonly required to attach a metallic shielding thereon to prevent EMI (Electro Magnetic Interference) from outer environments.
Actually, attaching an EMI shielding onto an insulative housing of a cable end connector has been widely utilized in the arts, the related prior arts are disclosed in U.S. Pat. Nos. 6,162,086 and 6,179,662, but these prior arts all have certain shortcomings which do not meet either the requirement of ensuring high-speed signal transmission or keeping low profile figuration of the connector.
U.S. Pat. No. 6,162,086 discloses a conventional cable assembly having an outer EMI shielding. The cable is arranged into the housing of the connector from a top wall of the connector, which leads to the whole height of the connector in a substrate rises when the connector is mounted to the substrate. Correspondingly, more space is occupied as a result of the higher configuration of the connector. If the connector is applied to an electronic device requiring a small dimension, it might not meet the requirement of low profile configuration.
U.S. Pat. No. 6,179,662 discloses another conventional cable assembly. Its improvement in comparison with what is disclosed in U.S. Pat. No. 6,162,086 is that the cable is arranged into the housing of the one of transverse end walls of the connector housing. Therefore, the whole height of the cable assembly is decreased. However, the cable assembly still has some disadvantages which influence signal transmission performance when the cable assembly is utilized to transmit high-speed signal. As described in the prior art, each terminal in the housing of the connector is connected with a corresponding signal wire of the cable, and the wire which is farthest to the end wall is longer than the wire which is nearest to the end wall. The length difference between the farthest and the nearest wires is substantially the longitudinal length of the connector. When the cable is applied to transmit a high speed signal, the apparent length difference of the signal wires impairs the synchronicity and accuracy of the signal transmission.
Therefore, it is necessary to develop an improved low profile cable assembly to overcome the above shortcomings.
An object of the present invention is to provide a cable assembly having an improved EMI shielding which has a minimized low-profile configuration as well as maintaining excellent EMI performance.
Another object of the present invention is to provide an metallic shielding for a low profile cable end connector, which can be easily assembled to the connector and can keep low-profile configuration of the connector.
To fulfill the above objects, a cable assembly in accordance with the present invention comprises a cable having a plurality of wires and two low profile cable end connector respectively connected with one end of the cable. The connector includes an insulative housing having a plurality of electrical terminals received therein. The housing has a mating surface adapted to mating with a mating connector. A metallic shielding is attached to the housing functioning as an EMI shielding. The shielding substantially surrounds the housing, and has a first opening in alignment with the mating surface of the housing and a second opening formed near a middle portion of one side wall of the shielding adapted to allow the wires of the cable to extend therethrough thereby establishing an electrical connection with the terminals in the housing. The wires of the cable are terminated to terminals of the connector by Insulation Displacement Contact (IDC) technology.
The shielding further has a locking portion extending outwardly from adjacent the second opening. The locking portion forms a latching end at a free end thereof for fastening to an EMI shielding of the cable thereby establishing an overall EMI protection throughout the cable assembly. The clamping portion can be a clasp or a crimping end.